There is a significant unmet clinical need for modular and customized porous biodegradable constructs (scaffolds) for non-union large bone loss injuries. This paper proposes modelling and biomanufacturing of modular and customizable porous constructs for patient-specific critical bone defects. A computational geometry-based algorithm was developed to model modular porous constructs using a parametric femur model based on the frequency of common injuries. The generated modular constructs are used to generate biomimetic path planning for three-dimensional (3D) printing of modular scaffold pieces. The developed method can be used for regenerating bone tissue for treating non-union large bone defects.